Phytochemicals as novel agents for the induction of browning in white adipose tissue

Plant Secondary Compounds Promote White Adipose Tissue Browning via Modulation of the Gut Microbiota in Small Mammals

The browning of white adipose tissue (WAT) is a promising area of research for treating metabolic disorders and obesity in the future. However, studies on plant secondary compounds promoting WAT browning are limited. Herein, we explored the effects of swainsonine (SW) on gut microbiota and WAT browning in captive pikas. SW inhibited body mass gain, increased brown adipose tissue (BAT) mass, and induced WAT browning in pikas. The 16S rDNA sequencing revealed a significant reduction in the alpha diversity and altered community structure of the gut microbiota in captive pikas. However, the addition of SW to the diet significantly increased the alpha diversity of gut microbiota and the relative abundance of Akkermansia, Prevotella, and unclassified_f__Lachnospiraceae, along with the complexity of the microbial co-occurrence network structure, which decreased in the guts of captive pikas. Functional profiles showed that SW significantly decreased the relative abundances of energy metabolism, lipid metabolism, and glycan biosynthesis and metabolism, which were enriched in captive pikas. Furthermore, SW decreased deterministic processes of gut microbiota assembly in July and increased them in November. Finally, the genera Prevotella and unclassified_f__Prevotellaceae were positively correlated with BAT mass. Our results highlighted that plant secondary compounds promote WAT browning by modulating the gut microbiota in small mammals.

A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity

Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

Mei-Gin Formula Ameliorates Obesity through Lipolysis, Fatty Oxidation, and Thermogenesis in High-Fat Diet-Induced Obese Rats

Obesity is a metabolic dysfunction characterized by excessive body fat deposition as a consequence of an energy imbalance. Novel therapeutic strategies have emerged that are safe and have comparatively low side effects for obesity treatment. Functional foods and nutraceuticals have recently received a great deal of attention because of their components with the properties of antimetabolic syndrome. Based on our previous in vitro and in vivo investigations on anti-adipogenesis activity and improved body fat accumulation in serials, the combination of three ingredients (including bainiku-ekisu, black garlic, and Mesona procumbens Hemsl), comprising the Mei-Gin formula (MGF), was eventually selected as a novel inhibitor that exhibited preventive effects against obesity. Herein, we verify the anti-obesity effects of MGF in obese rats induced by a high-fat diet and discuss the potential molecular mechanisms underlying obesity development. Oral administration of MGF significantly suppressed the final body weight, weight change, energy and water intake, subcutaneous and visceral fat mass, liver weight, hepatic total lipids and triglycerides (TG), and serum levels of TG, triglycerides (TC), low-density lipoprotein cholesterol (LDL-C), alanine transaminase (AST), uric acid, and ketone bodies and augmented fecal total lipids, TG, and cholesterol excretion in the high-dose MGF-supplemented groups. Furthermore, the corresponding lipid metabolic pathways revealed that MGF supplementation effectively increased lipolysis and fatty acid oxidation gene expression and attenuated fatty acid synthesis gene expression in the white adipose tissue (WAT) and liver and it also increased mitochondrial activation and thermogenic gene expression in the brown adipose tissue (BAT) of rats with obesity induced by a high-fat diet (HFD). These results demonstrate that the intake of MGF can be beneficial for the suppression of HFD-induced obesity in rats through the lipolysis, fatty oxidation, and thermogenesis pathway. In conclusion, these results demonstrate the anti-obesity efficacy of MGF in vivo and suggest that MGF may act as a potential therapeutic agent against obesity.

Albizia julibrissin Exerts Anti-Obesity Effects by Inducing the Browning of 3T3L1 White Adipocytes

This study investigated the effects of the Albizia julibrissin Leaf extracts (AJLE) on adipocytes using 3T3-L1 cells. AJLE inhibited adipogenesis by reducing the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding proteins (C/EBPs) that regulate enzymes involved in fat synthesis and storage, and subsequently reduced intracellular lipid droplets, glycerol-3-phosphate dehydrogenase (GPDH), and triglyceride (TG). AJLE also increased the expression of brown adipocyte markers, such as uncoupling protein-1 (UCP-1), PR/SET domain 16 (PRDM16), and bone morphogenetic protein 7 (BMP7) by inducing the differentiation of brown adipocytes, as shown by a decrease in the lipid droplet sizes and increasing mitochondrial mass. AJLE increased the expression of transcription factor A, mitochondrial (TFAM), mitochondrial DNA (mtDNA) copy number, and UCP-1 protein expression, all of which are key factors in regulating mitochondrial biogenesis. AJLE-induced browning was shown to be regulated by the coordination of AMPK, p38, and SIRT1 signaling pathways. The ability of AJLE to inhibit adipogenesis and induce brown adipocyte differentiation may help treat obesity and related diseases.

Cyclopia intermedia (Honeybush) Induces Uncoupling Protein 1 and Peroxisome Proliferator-Activated Receptor Alpha Expression in Obese Diabetic Female db/db Mice

Previously, we reported that a crude polyphenol-enriched fraction of Cyclopia intermedia (CPEF), a plant consumed as the herbal tea, commonly known as honeybush, reduced lipid content in 3T3-L1 adipocytes and inhibited body weight gain in obese, diabetic female leptin receptor-deficient (db/db) mice. In the current study, the mechanisms underlying decreased body weight gain in db/db mice were further elucidated using western blot analysis and in silico approaches. CPEF induced uncoupling protein 1 (UCP1, 3.4-fold, p < 0.05) and peroxisome proliferator-activated receptor alpha (PPARα, 2.6-fold, p < 0.05) expression in brown adipose tissue. In the liver, CPEF induced PPARα expression (2.2-fold, p < 0.05), which was accompanied by a 31.9% decrease in fat droplets in Hematoxylin and Eosin (H&E)-stained liver sections (p < 0.001). Molecular docking analysis revealed that the CPEF compounds, hesperidin and neoponcirin, had the highest binding affinities for UCP1 and PPARα, respectively. This was validated with stabilising intermolecular interactions within the active sites of UCP1 and PPARα when complexed with these compounds. This study suggests that CPEF may exert its anti-obesity effects by promoting thermogenesis and fatty acid oxidation via inducing UCP1 and PPARα expression, and that hesperidin and neoponcirin may be responsible for these effects. Findings from this study could pave the way for designing target-specific anti-obesity therapeutics from C. intermedia.

Acacetin alleviates energy metabolism disorder through promoting white fat browning mediated by AC-cAMP pathway

Acacetin (ACA), a flavone isolated from Chinese traditional medical herbs, has numerous pharmacological activities. However, little is known about the roles in white fat browning and energy metabolism. In the present study, we investigated whether and how ACA would improve energy metabolism in vivo and in vitro. ACA (20 mg/kg) was intraperitoneally injected to the mice with obesity induced by HFD for 14 consecutive days (in vivo); differentiated 3T3-L1 adipocytes were treated with ACA (20 µmol/L and 40 µmol/L) for 24 h (in vitro). The metabolic profile, lipid accumulation, fat-browning and mitochondrial contents, and so on were respectively detected. The results in vivo showed that ACA significantly reduced the body weight and visceral adipose tissue weight, alleviated the energy metabolism disorder, and enhanced the browning-related protein expressions in adipose tissue of rats. Besides, the data in vitro revealed that ACA significantly reduced the lipid accumulation, induced the expressions of the browning-related proteins and cAMP-dependent protein kinase A (PKA), and increased the mitochondrium contents, especially enhanced the energy metabolism of adipocytes; however, treatment with beta-adrenergic receptor blocker (propranolol, Pro) or adenyl cyclase (AC) inhibitor (SQ22536, SQ) abrogated the ACA-mediated effects. The data demonstrate that ACA alleviates the energy metabolism disorder through the pro-browning effects mediated by the AC-cAMP pathway. The findings would provide the experimental foundation for ACA to prevent and treat obesity and related metabolism disorders.

Effect of Abutilon indicum (L) Extract on Adipogenesis, Lipolysis and Cholesterol Esterase in 3T3-L1 Adipocyte Cell Lines

Abutilon indicum (L) is an Indian traditional plant used for the treatment of diabetes and heart diseases. The present study is to evaluate the functional of A. indicum leaf extract as insulin like character to inhibit lipolysis and stimulates Adipogenesis activity. The ability of the A. indicum leaf extract in anti-obesity effect of Adipogenesis, lipolysis and cholesterol esterase functions can be predicted by using 3T3-L1 adipocyte cell lines. Substances were isolated from A. indicum leaves and the double filtered crude sample were used for Adipogenesis, lipolysis and cholesterol esterase activity using 3T3-L1 adipocytes at different concentrations. We used differential media-I, differential media-II and maintenance media (MM1) at concentrations of 20, 40, 60, 80, 100, 200 and 400 µg/mL respectively. In addition to the extract, there is a significance increase in glycerol release (p < 0.001) compared with crude and reference compounds. Cholesterol esterase activity predicts the IC50 = 27.11 µg/mL of orlistat positive control compare with IC50 = 8.158 µg/mL of crude extract. Based on the observation, A. indicum leaf extract can promotes lipolysis and differentiated adipocytes. It is potentially used as adjuvant in the treatment of Type 2 diabetes.

(20R)-panaxadiol improves obesity by promoting white fat beigeing

Introduction: Obesity is an important cause of a range of metabolic diseases. However, the complex mechanisms of obesity and its related diseases make some weight loss methods ineffective or have safety issues. Ginseng, a specialty of Jilin Province in China with both edible and medicinal value, contains mainly ginsenosides and other components. In order to study the anti-obesity effect of ginseng, network pharmacology was used to predict and screen the active ingredients, action targets and signaling pathways of ginseng. We found (20R)-panaxadiol (PD) is a more desirable active ingredient due to its high drug-like properties and high bioavailability. Moreover, it is closely related to cAMP pathway which is more important in metabolism regulation. The corresponding pharmacodynamic targets of PD include ADRB2 (the gene encoding the β₂-adrenoceptor receptor). Our study aimed to investigate whether Panaxadiol can promote white adipocyte beigeing and increase thermogenesis through modulating the β₂/cAMP pathway to exert anti-obesity effects. Methods: In vivo, we established high-fat feeding obesity model, genotypically obese mice (ob/ob) model, and administered PD (10 mg/kg). PD treatment in ob/ob mice along with β₂ receptor inhibitor ICI118551. In vitro, differentiated mature 3T3-L1 cells were given palmitate (PA) to induce hypertrophy model along with PD (20 μM). Results: The results of this study demonstrated that PD significantly reduced body weight, improved glucose tolerance and lipid levels in high-fat-induced obese mice and ob/ob mice, and also reduced lipid droplet size in PA-treated hypertrophic adipocytes in vitro. Molecular biology assays confirmed that cAMP response element binding protein (CREB) phosphorylation was increased after PD administration, and the expression of thermogenesis-related proteins UCP1, PRDM16 and mitochondrial biosynthesis-related proteins PGC-1α, TFAM and NRF1 were increased. Molecular docking results showed a low binding energy between β₂ receptors and PD, indicating an affinity between the β₂ receptor and PD. In addition, the β₂ receptor inhibition, reversed the anti-obesity effect of PD on the body weight, lipid droplets, the expression of thermogenesis-related proteins and CREB phosphorylation in ob/ob mice. Discussion: These results suggest that PD may promote the expression of thermogenic proteins through phosphorylation of CREB via β2 receptor activation, and thus exert anti-obesity effects.

Quercetin-3-O-rutinoside from Moringa oleifera Downregulates Adipogenesis and Lipid Accumulation and Improves Glucose Uptake by Activation of AMPK/Glut-4 in 3T3-L1 Cells

Natural product-based therapeutic alternatives have drawn immense interest to deal with growing incidence of metabolic disorders. Rutin (quercetin-3-O-rutinoside) is found in a variety of fruits, vegetables, and plant beverages. In the present study, rutin was isolated from Moringa oleifera Lam., leaves and its anti-lipidemic and anti-adipogenic activity was evaluated through inhibition of key digestive enzymes and in vitro cell culture experiments using 3T3-L1 adipocytes. Rutin treatment substantially reduced α-glucosidase and pancreatic lipase activities with IC₅₀ values of 40 and 35 μg/ml, respectively. MTT assay with 3T3-L1 cells demonstrated the non-toxic effect of rutin up to 160 μg/ml. Oil Red O-stained images of rutin-treated 3T3-L1 cells depicted that rutin considerably reduced lipid content and adipogenesis (79.9%), and enhanced glycerol release in 3T3-L1 cells when compared to untreated cells. Rutin significantly (p < 0.05) enhanced glucose uptake in 3T3-L1 adipocytes and also led to reduced levels of leptin but enhanced levels of adiponectin. Western blot analysis of rutin-treated (40 µg/ml) adipocytes showed phosphorylation of AMPK, upregulated expression of Glut-4 (1.31-fold) and UCP-1 (1.47-fold), but downregulated expression of PPAR-γ by 0.73-fold. At transcriptional level, similar trends were observed in the mRNA expression of the above genes, except AMPK. Our results demonstrate that rutin isolated from M. oleifera significantly alleviates lipid content and adipogenesis, and improves glucose uptake through regulating PPAR-γ and AMPK signaling pathways; thus, rutin can be considered as a potential therapeutic agent against adiposity and glucose intolerance.

Graphical Abstract

Association of dietary phytochemical index with metabolically unhealthy overweight/obesity phenotype among Iranian women: A cross-sectional study

Background

Phytochemicals have been recently studied as adjuvants for the treatment of obesity. No study has investigated the association of phytochemical-rich foods with metabolically unhealthy overweight/obesity phenotype (MUOW/O). This study aimed to determine the association of dietary phytochemical index (DPI) with MUOW/O based on Karelis criteria among Iranian female adults.

Methods

In this cross-sectional study, a total of 228 overweight and obese women aged 18–48 years were included. Anthropometric measurements were evaluated for all participants. A validated 147-item Food Frequency Questionnaire (FFQ) was used for dietary assessment. DPI was calculated as [dietary energy derived from phytochemical-rich foods (kcal)/total daily energy intake (kcal)] × 100. Participants’ body composition and biochemical parameters of Karelis criteria [triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), insulin, and high-sensitivity C-reactive protein (hs-CRP)] were determined.

Results

The mean age of the study participants was 36.69 ± 9.20, and the mean DPI score was 26.23 ± 9.48 among participants with MUOW/O phenotype. After controlling for potential confounders, women in the highest tertile of DPI had lower odds for MUOW/O phenotype [odds ratio (OR): 0.23, 95% confidence interval (CI): 0.07–0.68, P = 0.008] compared to the lowest tertile. Among the components of Karelis criteria, homeostatic model assessment for insulin resistance (HOMA-IR) was significantly associated with MUOW/O phenotype in the fully adjusted model (OR: 0.29, 95% CI: 0.10–0.79, P = 0.01).

Conclusion

We found a significant association between DPI and MUOW/O phenotype in Iranian women. Prospective studies are needed to confirm these findings.

Sargassum thunbergii Extract Attenuates High-Fat Diet-Induced Obesity in Mice by Modulating AMPK Activation and the Gut Microbiota

Sargassum thunbergii (Mertens ex Roth) Kuntze (ST) is a brown alga rich in indole-2-carboxaldehyde. This study aimed to investigate the anti-obesity effects of ethanol extract from ST in in vitro and in vivo models. In 3T3-L1 cells, ST extract significantly inhibited lipid accumulation in mature adipocytes while lowering adipogenic genes (C/epba and Pparg) and enhancing metabolic sensors (Ampk, Sirt1), thermogenic genes (Pgc-1a, Ucp1), and proteins (p-AMPK/AMPK and UCP1). During animal investigation, mice were administered a chow diet, a high-fat diet (HF), or an HF diet supplemented with ST extract (at dosages of 150 and 300 mg/kg bw per day) for 8 weeks (n = 10/group). ST extract administration decreased weight gain, white adipose tissue weight, LDL-cholesterol, and serum leptin levels while improving glucose intolerance. In addition, ST extract increased the expression of Ampk and Sirt1 in adipose tissue and in the liver, as well as p-AMPK/AMPK ratio in the liver, compared to HF-fed mice. The abundance of Bacteroides vulgatus and Faecalibacterium prausnitzii in the feces increased in response to ST extract administration, although levels of Romboutsia ilealis decreased compared with those in HF-fed mice. ST extract could prevent obesity in HF-fed mice via the modulation of AMPK activation and gut microbiota composition.

High-intensity interval training with or without chlorella vulgaris supplementation in obese and overweight women: effects on mitochondrial biogenesis, performance and body composition

The beneficial effects of high-intensity interval training (HIIT) and chlorella vulgaris (CV) on body composition and mitochondrial biogenesis have been shown in some mechanistic studies. This study aimed to determine the effects of CV and/or HIIT on mitochondrial biogenesis, performance and body composition among overweight/obese women. There was a significant reduction in the fat mass (FM) of the CV + HIIT group, as compared with the placebo group (P = 0·005). A marginal significant increase in body water (P = 0·050) and PPAR-γ coactivator-1α (P = 0·050) was also found only in the CV + HIIT group, as compared with the placebo. Relative (P < 0·001) and absolute (P < 0·001) VO_2max, as well as Bruce MET (P < 0·001), were significantly increased in the HIIT and HIIT + CV groups. Besides, the synergistic effect of CV and HIIT on the Bruce MET increment was found (interaction P-value = 0·029). No significant changes were observed in BMI, fat-free mass, visceral fat, silent information regulator 1 and fibroblast growth factor-21. In this randomised clinical trial, forty-six overweight/obese women were assigned to four groups including CV + HIIT and HIIT + placebo groups that received three capsules of CV (300 mg capsules, three times a day) or corn starch, in combination with three sessions/week of HIIT. CV and placebo groups only received 900 mg of CV or corn starch, daily, for 8 weeks. Biochemical assessments, performance assessment and body composition were obtained at the beginning and end of the intervention. HIIT may be, therefore, effective in improving mitochondrial biogenesis, performance and body composition in overweight/obese women.

Cross-Talk between Obesity and Diabetes: Introducing Polyphenols as an Effective Phytomedicine to Combat the Dual Sword Diabesity

: Obesity-associated diabetes mellitus, a chronic metabolic affliction accounting for 90% of all diabetic patients, has been affecting humanity extremely badly and escalating the risk of developing other serious disorders. It is observed that 0.4 billion people globally have diabetes, whose major cause is obesity. Currently, innumerable synthetic drugs like alogliptin and rosiglitazone are being used to get through diabetes, but they have certain complications, restrictions with severe side effects, and toxicity issues. Recently, the frequency of plant-derived phytochemicals as advantageous substitutes against diabesity is increasing progressively due to their unparalleled benefit of producing less side effects and toxicity. Of these phytochemicals, dietary polyphenols have been accepted as potent agents against the dual sword "diabesity". These polyphenols target certain genes and molecular pathways through dual mechanisms such as adiponectin upregulation, cannabinoid receptor antagonism, free fatty acid oxidation, ghrelin antagonism, glucocorticoid inhibition, sodium-glucose cotransporter inhibition, oxidative stress and inflammation inhibition etc. which sequentially help to combat both diabetes and obesity. In this review, we have summarized the most beneficial natural polyphenols along with their complex molecular pathways during diabesity.

(20R)-Panaxadiol as a Natural Active Component with Anti-Obesity Effects on ob/ob Mice via Modulating the Gut Microbiota

Obesity is an important cause of diseases such as type 2 diabetes, non-alcoholic fatty liver and atherosclerosis. The use of ingredients extracted from traditional Chinese medicine for weight loss is now receiving more and more attention. Ginseng has been recorded since ancient times for the treatment of diabetes. The (20R)-Panaxadiol (PD) belongs to the ginseng diol type compounds, which are moderately bioavailable and may remain in the intestinal tract for a longer period of time. This study investigated the potential positive effect of PD in ob/ob mice and evaluated its effect against obesity. The ob/ob mice were administered PD for ten weeks. Our study showed that PD could improve obesity, glucose tolerance disorder, as well as gut dysbiosis. Panaxadiol decreased ob/ob mice’s Firmicutes/Bacteroidetes (F/B). Furthermore, 16S rRNA gene sequencing of the fecal microbiota suggested that PD changed the composition of the gut microbiota in ob/ob mice and modulated specific bacteria such as lactobacillus, prevotellace and so on. Moreover, PD improved the intestinal wall integrity. In conclusion, our results suggest that (20R)-Panaxadiol, as an active ingredient of the traditional Chinese medicinal herb ginseng, may improve obesity to some extent via improving gut microbiota

Butein-Enriched Fractions of Butea monosperma (Lam.) Taub. Flower Decrease Weight Gains and Increase Energy Expenditure in High-Fat Diet-Induced Obese Mice

Butea monosperma (Lam.) Taub. has been applied to treat inflammatory, metabolic, and infectious diseases. However, the antiobesity effects of B. monosperma (Lam.) Taub. flower (BMF) and the underlying mechanisms have not been determined. In this study, we analyzed the various extraction procedures, investigated the antiobesity effects, and identified the main chemical constituents of BMF. The BMF was subjected to acid hydrolysis in 5% H₂SO₄ in methanol at 50°C for 48 h and partitioned with ethyl acetate. The acid-hydrolyzed BMF ethyl acetate extracts (BMFE) strongly induced the expression of uncoupling protein 1 (Ucp1) and other thermogenic genes in C3H10T1/2 adipocytes. Daily oral administration of 70 mg/kg BMFE (BMFE70) to mice with diet-induced obesity resulted in less body weight gain, increased glucose tolerance, higher rectal temperature, and increased oxygen consumption. Qualitative and quantitative analyses along with treatments in Akt1 knockout mouse embryonic fibroblasts indicate that butein is a major active ingredient of BMFE, which stimulates Ucp1 gene expression. These data show the effects of butein-containing B. monosperma flower extract on thermogenesis and energy expenditure, further suggesting the potential role of BMFE as a functional ingredient in obesity and related metabolic diseases.

Green tea aqueous extract (GTAE) prevents high-fat diet-induced obesity by activating fat browning

Adipose browning leads to increased energy expenditure and reduced adiposity and has, therefore, become an attractive therapeutic strategy for obesity. In this study, we elucidated the effect of green tea aqueous extract (GTAE) on the browning of inguinal white adipose tissue (Ing-WAT) and brown adipose tissue (BAT) in high-fat diet (HFD)-fed mice. The main phytochemical components identified in GTAE through high-performance liquid chromatography (HPLC) included (-)-gallocatechin, (-)-epigallocatechin, (-)-catechin, (-)-epigallocatechin-3-gallate, caffeine, (-)-epicatechin, (-)-gallocatechin gallate, and (-)-epicatechin-3-gallate. Daily supplementation with 1% GTAE for 12 weeks markedly reduced bodyweight gain, systemic inflammation, oxidative stress, and improved insulin resistance. Additionally, histological analysis revealed that dietary supplementation with 1% GTAE reversed HFD-induced adipocyte size and hepatic steatosis. These effects were associated with activation of browning in the Ing-WAT and BAT, which mediate systemic metabolic dysfunction in HFD-fed mice. Taken together, our data support the use of GTAE, a natural product, for the attenuation of obesity through the activation of fat browning.

Adipose and non-adipose perspectives of plant derived natural compounds for mitigation of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity.

AIM OF THIS REVIEW

The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets.

MATERIALS AND METHODS

PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from "The Plant List" (www.theplantlist.org) or MPNS (http://mpns.kew.org).

RESULTS

Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity.

CONCLUSION

Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.

Food phenolics stimulate adipocyte browning via regulating gut microecology

Fat browning has piqued the interest of researchers as a potential target for treating obesity and related metabolic disorders. Recruitment of brown adipocytes leads to enhanced energy dissipation and reduced adiposity, thus facilitating the maintenance of metabolic homeostasis. Evidence is increasing to support the crucial roles of polyphenols and gut microecology in turning fat "brown". However, it is not clear whether the intestinal microecology is involved in polyphenol-mediated regulation of adipose browning, so this concept is worthy of exploration. In this review, we summarize the current knowledge, mostly from studies with murine models, supporting the concept that the effects of food phenolics on brown fat activation and white fat browning can be attributed to their regulatory actions on gut microecology, including microbial community profile, gut metabolites, and gut-derived hormones. Furthermore, the potential underlying pathways involved are also discussed. Basically, understanding gut microecology paves the way to determine the underlying roles and mechanisms of food phenolics in adipose browning.

The capacity of differentiation of stromal vascular fraction cells into beige adipocytes is markedly reduced in subjects with overweight/obesity and insulin resistance: effect of genistein

BACKGROUND

Dietary bioactive compounds have been demonstrated to produce several health benefits. Genistein, an isoflavone of soy protein, and resveratrol, a polyphenol from grapes, have been shown to improve insulin sensitivity and to stimulate white adipose tissue (WAT) browning, leading to increased energy expenditure. However, it has not been demonstrated in humans whether genistein or resveratrol have the capacity to stimulate the differentiation of stromal vascular fraction (SVF) cells from white fat into beige adipocytes.

SUBJECTS/METHODS

With this aim, we assessed whether stromal vascular fraction cells obtained from biopsies of the subdermal fat depots of subjects with normal body weight (NW) or from subjects with overweight/obesity with (OIR) or without (OIS) insulin resistance were able to differentiate into the beige adipose tissue lineage in vitro, by exposing the cells to genistein, resveratrol, or the combination of both.

RESULTS

The results showed that SVF cells obtained from NW or OIS subjects were able to differentiate into beige adipocytes according to an increased expression of beige biomarkers including UCP1, PDRM-16, PGC1α, CIDEA, and SHOX2 upon exposure to genistein. However, SVF cells from OIR subjects were unable to differentiate into beige adipocytes with any of the inducers. Exposure to resveratrol or the combination of resveratrol/genistein did not significantly stimulate the expression of browning markers in any of the groups studied. We found that the non-responsiveness of the SVF from subjects with obesity and insulin resistance to any of the inducers was associated with an increase in the expression of endoplasmic reticulum stress markers.

CONCLUSION

Consumption of genistein may stimulate WAT browning mainly in NW or OIS subjects. Thus, obesity associated with insulin resistance may be considered as a condition that prevents some beneficial effects of some dietary bioactive compounds.

Endocrine disrupting chemicals: Friend or foe to brown and beige adipose tissue?

The effects of Endocrine Disrupting Chemicals (EDCs) on the current obesity epidemic is a growing field of interest. Numerous EDCs have shown the potential to alter energy metabolism, which may increase the risk of obesity, in part, through direct actions on adipose tissue. While white adipose tissue has historically been the primary focus of this work, evidence of the EDC-induced disruption of brown and beige adipose tissues continues to build. Both brown and beige fat are thermogenic adipose depots rich in mitochondria that dispense heat when activated. Due to these properties, brown and beige fat are implicated in metabolic diseases such as obesity, diabetes, and cachexia. This review delves into the current literature of different EDCs, including bisphenols, dioxins, air pollutants, phthalates, and phytochemicals. The possible implications that these EDCs have on thermogenic adipose tissues are covered. This review also introduces the possibility of using brown and beige fat as a therapeutic target organ by taking advantage of some of the properties of EDCs. Collectively, we provide a comprehensive discussion of the evidence of EDC disruption in white, brown, and beige fat and highlight gaps worthy of further exploration.

A Standardized Aframomum melegueta Seed Extract Regulates Browning of White Adipose Tissue in High-Fat Diet Model Mice

Thermogenesis-mediated energy expenditure is a promising strategy to combat obesity. Aframomum melegueta commonly known as grains of paradise (GP) is a popular spice with medicinal attributes in promoting health. We have demonstrated the thermogenic effects of a standardized A melegueta seed extract (AMSE) containing not <10% 6-paradol in high fat diet-fed (HFD) mice. The 6-week oral ingestion of 20 and 40 mg/kg AMSE significantly limited the weight gain, improved the brown adipose tissue (BAT) activity in HFD mice. Interestingly, AMSE markedly induced the beige adipocytes in epididymal white adipose tissue (eWAT). AMSE treatment led to the upregulation of marker proteins i.e., uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor-gamma-coactivator 1-alpha (PGC-1α), and peroxisome proliferator-activated receptor gamma (PPARγ) in eWAT and BAT. Our findings add to the current understanding of the thermogenic potentials of GP seed extract and report that the extract can stimulate the browning of WATs in addition to enhanced BAT activity. AMSE requires clinical validation to be explored as a dietary supplement/functional ingredient with thermogenic effect in food and beverages.

Ellagic acid induces beige remodeling of white adipose tissue by controlling mitochondrial dynamics and SIRT3

To determine whether ellagic acid (EA) induces the "beige remodeling" of white adipose tissue (WAT), we treated cold-exposed mice and mouse stromal vascular fraction (SVF) cells with EA, a phytochemical abundant in fruits and vegetables, in particular berries. We then investigated the mechanism of EA in beige remodeling with a particular focus on DRP1-mediated mitochondrial fission and SIRT3. EA induced the trans-differentiation of white adipocytes to beige adipocytes by promoting the expression of UCP1 and other brown and beige adipocytes/fat factors (PRDM16, UCP1, PGC1α, CD137, and TBX1) and mitochondrial dynamics-related factors (SIRT3, NRF1, CPT1β, DRP1, and FIS1) in 3T3-L1/SVF cells, and these were confirmed in the inguinal WAT of a cold-exposed mouse model. The browning effect of EA was abolished by a potent DRP1 inhibitor Mdivi-1 or SIRT3 knockdown, suggesting that EA induces beige remodeling of WAT by regulating the mitochondrial dynamics and SIRT3.

Effects of Bacillus Subtilis-Fermented White Sword Bean Extract on Adipogenesis and Lipolysis of 3T3-L1 Adipocytes

To investigate the adipogenesis and lipolysis effects of the Bacillus subtilis-fermented white sword bean extract (FWSBE) on 3T3-L1 adipocytes, we treated 3T3-L1 preadipocytes before and after differentiation with FWSBE and measured triglyceride, free glycerol, mRNA, and protein levels. First, FWSBE reduced the cell viability of 3T3-L1 pre-adipocytes under 1000 µg/mL conditions. Triglyceride accumulation in 3T3-L1 pre-adipocytes was suppressed, and free glycerol content in mature 3T3-L1 adipocytes was increased in the FWSBE treatment groups, indicating that FWSBE has anti-obesity effects. Further, FWSBE suppressed adipogenesis in 3T3-L1 pre-adipocytes by lowering the protein levels of C/EBPα, PPARγ, and FAS and increasing the level of pACC and pAMPK. Additionally, FWSBE promoted lipolysis in mature 3T3-L1 adipocytes by increasing the transcription levels of Ppara, Acox, and Lcad and the protein levels of pHSL and ATGL. Thus, we suggest that FWSBE can be a potential dietary supplement because of its anti-obesity properties.

Activation of AMP-Activated Protein Kinase-Sirtuin 1 Pathway Contributes to Salvianolic Acid A-Induced Browning of White Adipose Tissue in High-Fat Diet Fed Male Mice

Background: Salvianolic acid A (Sal A), a natural polyphenolic compound extracted from Radix Salvia miltiorrhiza (Danshen), exhibits exceptional pharmacological activities against cardiovascular diseases. While a few studies have reported anti-obesity properties of Sal A, the underlying mechanisms are largely unknown. Given the prevalence of obesity and promising potential of browning of white adipose tissue to combat obesity, recent research has focused on herbal ingredients that may promote browning and increase energy expenditure.

Purpose: The present study was designed to investigate the protective antiobesity mechanisms of Sal A, in part through white adipose browning.

Methods: Both high-fat diet (HFD)-induced obese (DIO) male mice model and fully differentiated C3H10T1/2 adipocytes from mouse embryo fibroblasts were employed in this study. Sal A (20 and 40 mg/kg) was administrated to DIO mice by intraperitoneal injection for 13-weeks. Molecular mechanisms mediating effects of Sal A were evaluated.

Resluts: Sal A treatment significantly attenuated HFD-induced weight gain and lipid accumulation in epididymal fat pad. Uncoupling protein 1 (UCP-1), a specialized thermogenic protein and marker for white adipocyte browning, was significantly induced by Sal A treatment in both white adipose tissues and cultured adipocytes. Further mechanistic investigations revealed that Sal A robustly reversed HFD-decreased AMP-activated protein kinase (AMPK) phosphorylation and sirtuin 1 (SIRT1) expression in mice. Genetically silencing either AMPK or SIRT1 using siRNA abolished UCP-1 upregulation by Sal A. AMPK silencing significantly blocked Sal A-increased SIRT1 expression, while SIRT1 silencing did not affect Sal A-upregulated phosphorylated-AMPK. These findings indicate that AMPK was involved in Sal A-increased SIRT1.

Conclusion: Sal A increases white adipose tissue browning in HFD-fed male mice and in cultured adipocytes. Thus, Sal is a potential natural therapeutic compound for treating and/or preventing obesity.

A review of dietary phytochemicals and their relation to oxidative stress and human diseases

Phytochemicals refer to active substances in plant-based diets. Phytochemicals found in for example fruits, vegetables, grains and seed oils are considered relatively safe for consumption due to mammal-plant co-evolution and adaptation. A number of human diseases are related to oxidative stress caused by for example chemical environmental contaminants in air, water and food; while also lifestyle including smoking and lack of exercise and dietary preferences are important factors for disease development in humans. Here we explore the dietary sources of antioxidant phytochemicals that have beneficial effects on oxidative stress, cardiovascular and neurological diseases as well as cancer. Plant-based diets usually contain phenolic acids, flavonoids and carotenoids, which have strong antioxidant properties, and therefore remove the excess of active oxygen in the body, and protect cells from damage, reducing the risk of cardiovascular and Alzheimer's disease. In most cases, obesity is related to diet and inactivity and plant-based diets change lipid composition and metabolism, which reduce obesity related hazards. Cruciferous and Allium vegetables are rich in organic sulphides that can act on the metabolism of carcinogens and therefore used as anti-cancer and suppressing agents while dietary fibres and plant sterols may improve intestinal health and prevent intestinal diseases. Thus, we recommend a diet rich in fruits, vegetables, and grains as its content of phytochemicals may have the potential to prevent or improve a broad sweep of various diseases.

Supplementation of green coffee bean extract in healthy overweight subjects increases lean mass/fat mass ratio: A randomized, double-blind clinical study

Objective

In this study, we have demonstrated that supplementation of a complex of chlorogenic acid isomers (CGA-7^TM) could significantly mitigate the risk of obesity in healthy overweight subjects.

Method

In a double-blind, placebo-controlled clinical study, healthy overweight (body mass index ⩾ 25 to <30 kg/m²) male and female subjects (N = 71) were randomly allocated to receive 500 mg CGA-7 or placebo daily for 12 weeks. Changes in body weight and body mass index were recorded alongside vital signs and anthropometric measurements at week 4, 8 and 12. Body composition was assessed at baseline and the end of treatment using dual-energy X-ray absorptiometry. Safety analysis included serum biochemical and haematological assessments and measurement of vital signs. In addition, any adverse or serious adverse events were recorded during the study.

Results

Sixty subjects completed the study. Mean body weight and body mass index were significantly reduced in CGA-7 group as compared to placebo (p < 0.001). CGA-7 group showed significant changes in body fat (%), fat mass and lean mass in comparison with placebo group (1.38% ± 1.4% vs -0.22% ± 0.86%, 1.97 ± 1.44 kg vs -0.39 ± 1.31 kg; 0.81 ± 1.20 kg vs -0.13 ± 0.97 kg, p < 0.001). Consumption of CGA-7 significantly improved the serum lipid profile. Importantly, CGA-7 consumption in humans had no adverse effects and was well tolerated during the study. The blood biochemical and haematological parameters marginally varied in the treatment groups throughout the study.

Conclusion

To conclude, this study provides scientific validation of the functionality of green coffee bean extract and recommends the safety of the supplementation in healthy individuals.

Precision Nutrition to Activate Thermogenesis as a Complementary Approach to Target Obesity and Associated-Metabolic-Disorders

Simple Summary

Regarding the pandemic of obesity and chronic diseases associated to metabolic alterations that occur nowadays worldwide, here, we review the most recent studies related to bioactive compounds and diet derived ingredients with potential effects to augment the systemic energy expenditure. We specifically focus in two processes: the activation of thermogenesis in adipose tissue and the enhancement of the mitochondrial oxidative phosphorylation capacity in muscles. This may provide relevant information to develop diets and supplements to conduct nutritional intervention studies with the objective to ameliorate the metabolic and chronic inflammation in the course of obesity and related disorders.

Abstract

Obesity is associated to increased incidence and poorer prognosis in multiple cancers, contributing to up to 20% of cancer related deaths. These associations are mainly driven by metabolic and inflammatory changes in the adipose tissue during obesity, which disrupt the physiologic metabolic homeostasis. The association between obesity and hypercholesterolemia, hypertension, cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) is well known. Importantly, the retrospective analysis of more than 1000 epidemiological studies have also shown the positive correlation between the excess of fatness with the risk of cancer. In addition, more important than weight, it is the dysfunctional adipose tissue the main driver of insulin resistance, metabolic syndrome and all cause of mortality and cancer deaths, which also explains why normal weight individuals may behave as “metabolically unhealthy obese” individuals. Adipocytes also have direct effects on tumor cells through paracrine signaling. Downregulation of adiponectin and upregulation of leptin in serum correlate with markers of chronic inflammation, and crown like structures (CLS) associated to the adipose tissue disfunction. Nevertheless, obesity is a preventable risk factor in cancer. Lifestyle interventions might contribute to reduce the adverse effects of obesity. Thus, Mediterranean diet interventional studies have been shown to reduce to circulation inflammatory factors, insulin sensitivity and cardiovascular function, with durable responses of up to 2 years in obese patients. Mediterranean diet supplemented with extra-virgin olive oil reduced the incidence of breast cancer compared with a control diet. Physical activity is another important lifestyle factor which may also contribute to reduced systemic biomarkers of metabolic syndrome associated to obesity. In this scenario, precision nutrition may provide complementary approaches to target the metabolic inflammation associated to “unhealthy obesity”. Herein, we first describe the different types of adipose tissue -thermogenic active brown adipose tissue (BAT) versus the energy storing white adipose tissue (WAT). We then move on precision nutrition based strategies, by mean of natural extracts derived from plants and/or diet derived ingredients, which may be useful to normalize the metabolic inflammation associated to “unhealthy obesity”. More specifically, we focus on two axis: (1) the activation of thermogenesis in BAT and browning of WAT; (2) and the potential of augmenting the oxidative capacity of muscles to dissipate energy. These strategies may be particularly relevant as complementary approaches to alleviate obesity associated effects on chronic inflammation, immunosuppression, angiogenesis and chemotherapy resistance in cancer. Finally, we summarize main studies where plant derived extracts, mainly, polyphenols and flavonoids, have been applied to increase the energy expenditure.

Gomisin A Alleviates Obesity by Regulating the Phenotypic Switch between White and Brown Adipocytes

Although gomisin A (GA) alleviates cancer and inflammation, its anti-obesity effect and the underlying mechanism have not yet been elucidated. Therefore, in this study, we aimed to elucidate the anti-obesity effects of GA by investigating the phenotypic changes involved in the browning and whitening of adipocytes. Here, obesity was induced to C57BL/6J mice using a high-fat diet (HFD). We administrated GA and checked weight changes for 12 weeks. We found that GA decreased the weight of weight gain, epididymal white adipose tissue (eWAT), and liver in the mice. In addition, the administration of GA elevated the levels of high-density lipoprotein (HDL)-cholesterol in the mice serum. Moreover, even after 12 weeks of treatment with GA, it did not cause any hepatic and renal toxicity. However, we found that GA induced the browning of eWAT and inhibited the whitening of brown adipose tissue. We further confirmed the anti-obesity mechanism of GA using 3T3-L1 cells, the human adipose mesenchymal stem cells (hAMSCs), and primary brown adipocytes (BAs) in vitroexperiments. We found that GA suppressed adipogenesis via the activation of AMP-activated protein kinase (AMPK). Furthermore, GA-induced browning by increasing the expression levels of uncoupling protein 1 (UCP1) in hAMSCs. The results of our study indicate that GA can inhibit weight gain by regulating the phenotypic changes involved in the browning and whitening of adipose tissues, which makes it a potential therapeutic agent for the treatment of obesity.

Beige Adipose Tissue Identification and Marker Specificity-Overview

Adipose tissue (AT) is classified based on its location, physiological and functional characteristics. Although there is a clear demarcation of anatomical and molecular features specific to white (WAT) and brown adipose tissue (BAT), the factors that uniquely differentiate beige AT (BeAT) remain to be fully elaborated. The ubiquitous presence of different types of AT and the inability to differentiate brown and beige adipocytes because of similar appearance present a challenge when classifying them one way or another. Here we will provide an overview of the latest advances in BeAT, BAT, and WAT identification based on transcript markers described in the literature. The review paper will highlight some of the difficulties these markers pose and will offer new perspectives on possible transcript-specific identification of BeAT. We hope that this will advance the understanding of the biology of different ATs. In addition, concrete strategies to distinguish different types of AT may be relevant to track the efficacy and mechanisms around interventions aimed to improve metabolic health and thwart excessive weight gain.

Mechanisms of action for the anti-obesogenic activities of phytochemicals

The prevalence of obesity is increasing rapidly globally and has recently reached pandemic proportions. It is a multifactorial disorder linked to a number of non-communicable diseases such as type-2 diabetes, cardiovascular disease, and cancer. Over-nutrition and a sedentary lifestyle are considered the most significant causes of obesity; a healthy lifestyle and behavioural interventions are the most powerful ways to achieve successful weight loss, but to maintain this in the long term can prove difficult for many individuals, without medical intervention. Various pharmacological anti-obesogenic drugs have been tested and marketed in the past and have been moderately successful in the management of obesity, but their adverse effects on human health often outweigh the benefits. Natural products from plants, either in the form of crude extracts or purified phytochemicals, have been shown to have anti-obesogenic properties and are generally considered as nontoxic and cost-effective compared to synthetic alternatives. These plant products combat obesity by targeting the various pathways and/or regulatory functions intricately linked to obesity. Their mechanisms of action include inhibition of pancreatic lipase activities, an increase in energy expenditure, appetite regulation, lipolytic effects, and inhibition of white adipose tissue development. In this review, we discuss the distinct anti-obesogenic properties of recently reported plant extracts and specific bioactive compounds, along with their molecular mechanisms of action. This review will provide a common platform for understanding the different causes of obesity and the possible approaches to using plant products in tackling this worldwide health issue.

Angiotensin AT1 receptor antagonism by losartan stimulates adipocyte browning via induction of apelin

Adipocyte browning appears to be a potential therapeutic strategy to combat obesity and related metabolic disorders. Recent studies have shown that apelin, an adipokine, stimulates adipocyte browning and has negative cross-talk with angiotensin II receptor type 1 (AT₁ receptor) signaling. Here, we report that losartan, a selective AT₁ receptor antagonist, induces browning, as evidenced by an increase in browning marker expression, mitochondrial biogenesis, and oxygen consumption in murine adipocytes. In parallel, losartan up-regulated apelin expression, concomitant with increased phosphorylation of protein kinase B and AMP-activated protein kinase. However, the siRNA-mediated knockdown of apelin expression attenuated losartan-induced browning. Angiotensin II cotreatment also inhibited losartan-induced browning, suggesting that AT₁ receptor antagonism-induced activation of apelin signaling may be responsible for adipocyte browning induced by losartan. The in vivo browning effects of losartan were confirmed using both C57BL/6J and ob/ob mice. Furthermore, in vivo apelin knockdown by adeno-associated virus carrying-apelin shRNA significantly inhibited losartan-induced adipocyte browning. In summary, these data suggested that AT₁ receptor antagonism by losartan promotes the browning of white adipocytes via the induction of apelin expression. Therefore, apelin modulation may be an effective strategy for the treatment of obesity and its related metabolic disorders.

Trigonelline induces browning in 3T3-L1 white adipocytes

Trigonelline, a major alkaloid component of fenugreek, has been demonstrated to have several biological activities, including antidiabetic and anticancer effects. This study aimed to examine the possible application of trigonelline as an anti-obesity compound based on an investigation of its enhancement of lipid catabolism and induction of browning in white adipocytes. Trigonelline induces browning of 3T3-L1 white adipocytes by enhancing the expressions of brown-fat signature proteins and genes as well as beige-specific genes, including Cd137, Cited1, Tbx1, and Tmem26. Trigonelline also improves lipid metabolism in white adipocytes by decreasing adipogenesis and lipogenesis as well as promotes lipolysis and fatty acid oxidation. Moreover, trigonelline increases the expression of Cox4, Nrf1, and Tfam genes that are responsible for mitochondrial biogenesis. Mechanistic studies revealed that the browning effect of trigonelline in 3T3-L1 white adipocytes is mediated by activating β3-AR and inhibiting PDE4, thereby stimulating the p38 MAPK/ATF-2 signaling pathway. Considering its high bioavailability in humans and the results of this study, trigonelline may have potential as an anti-obesity compound.

Anti-Obesity Effects of Soybean Embryo Extract and Enzymatically-Modified Isoquercitrin

Soy isoflavones are bioactive phytoestrogens with known health benefits. Soybean embryo extract (SEE) has been consumed as a source of isoflavones, mainly daidzein, glycitein, and genistein. While previous studies have reported the anti-obesity effects of SEE, this study investigates their molecular mechanisms and the synergistic effects of co-treatment with SEE and enzymatically modified isoquercitrin (EMIQ). SEE upregulated genes involved in lipolysis and brown adipocyte markers and increased mitochondrial content in differentiated C3H10T1/2 adipocytes in vitro. Next, we use a high-fat diet-induced obesity mouse model to determine the anti-obesity effect of SEE. Two weeks of single or combined treatment with SEE and EMIQ significantly reduced body weight gain and improved glucose tolerance. Mechanistically, SEE treatment increased mitochondrial content and upregulated genes involved in lipolysis in adipose tissue through the cAMP/PKA-dependent signaling pathway. These effects required a cytosolic lipase adipose triglyceride lipase (ATGL) expression, confirmed by an adipocyte-specific ATGL knockout mouse study. Collectively, this study demonstrates that SEE exerts anti-obesity effects through the activation of adipose tissue metabolism and exhibits a synergistic effect of co-treatment with EMIQ. These results improve our understanding of the mechanisms underlying the anti-obesity effects of SEE related to adipose tissue metabolism.

The Gintonin-Enriched Fraction of Ginseng Regulates Lipid Metabolism and Browning via the cAMP-Protein Kinase a Signaling Pathway in Mice White Adipocytes

Obesity is a major health concern and is becoming an increasingly serious societal problem worldwide. The browning of white adipocytes has received considerable attention because of its potential protective effect against obesity-related metabolic disease. The gintonin-enriched fraction (GEF) is a non-saponin, glycolipoprotein component of ginseng that is known to have neuroprotective and anti-inflammatory effects. However, the anti-obesity and browning effects of GEF have not been explored to date. Therefore, we aimed to determine whether GEF has a preventive effect against obesity. We differentiated 3T3-L1 cells and mouse primary subcutaneous adipocytes for 8 days in the presence or absence of GEF, and then measured the expression of intermediates in signaling pathways that regulate triglyceride (TG) synthesis and browning by Western blotting and immunofluorescence analysis. We found that GEF reduced lipid accumulation by reducing the expression of pro-adipogenic and lipogenic factors, and increased lipolysis and thermogenesis, which may be mediated by an increase in the phosphorylation of protein kinase A. These findings suggest that GEF may induce fat metabolism and energy expenditure in white adipocytes and therefore may represent a potential treatment for obesity.

Secreted protein acidic and rich in cysteine (SPARC) regulates thermogenesis in white and brown adipocytes

SPARC, also known as osteonectin, is well known for its physiological roles in bone formation and tissue remodeling, as well as in cancer pathology; however, evidence regarding its function in adipocytes is lacking. The present study explored the physiological role of SPARC in cultured 3T3-L1 white and HIB1B brown adipocytes of murine cell lines. Treatment of recombinant SPARC upregulated the fat browning marker proteins and genes in white adipocytes and activated brown adipocytes. Conversely, knockdown of Sparc markedly reduced these genes and proteins in both cell lines. In addition, recombinant SPARC inhibited expression of adipogenic and lipogenic proteins but elevated lipolytic and fatty acid oxidation proteins. Furthermore, in silico analysis revealed that SPARC directly interacted and regulated VEGF in adipocytes. In conclusion, SPARC acts as a regulatory protein in both white and brown adipocytes by controlling thermogenesis and is thus regarded as a possible therapeutic target for treatment of obesity.

Ginsenoside Rd Ameliorates High Fat Diet-Induced Obesity by Enhancing Adaptive Thermogenesis in a cAMP-Dependent Manner

OBJECTIVE

With the discovery of thermogenic adipocytes in humans, it has been hypothesized that enhancing adaptive thermogenesis may improve obesity. Although many studies have found that ginseng can improve obesity, the beneficial effects of ginsenoside Rd on obesity and its mechanisms have not been studied.

METHODS

High-fat diet-induced obese mice were used as the study subjects, with intraperitoneal injection of Rd daily at a dose of 15 mg/kg. Body weight and energy metabolism were observed. The effects of Rd on glucose tolerance, insulin sensitivity, and cold tolerance were tested. The expression of genes associated with thermogenesis was analyzed. Finally, the mechanisms by which Rd regulates adaptive thermogenesis were studied.

RESULTS

Rd ameliorated obesity and insulin resistance. Rd increased cold tolerance through enhancing thermogenic gene expression in brown adipose tissue and increased the browning of white adipose tissue induced by cold stress. Rd increased intracellular cyclic adenosine monophosphate (cAMP) content. Decreasing intracellular cAMP levels by an inhibitor of adenylyl cyclase SQ22536 abolished the promoting effects of Rd on the expression of thermogenic genes.

CONCLUSIONS

Rd improves obesity and insulin resistance. The upregulation of thermogenesis by Rd is dependent on the cAMP/protein kinase A signaling pathway.

Lobularia maritima (L.) Desv. Aerial Parts Methanolic Extract: In Vitro Screening of Biological Activity

Lobularia maritima (L.) Desv. is a perennial herb growing wild in the Mediterranean basin. The aim of this work was to assess the fatty acid, terpene, phytosterol, and phenolic composition of the methanolic extract and its sub-fractions using Gas Chromatography-Mass Spectrometry (GC-MS), High-Performance Liquid Chromathography with Dioide-Array Detector (HPLC-DAD), High-Performance Liquid Chromathography-High Resolution Mass Spectrometry (HPLC-HRMS), and Electrospray Ionization Tandem Mass Spectrometry (ESI-MS/MS). The potential health benefits of this plant species have been investigated as well. The antioxidant activity was determined in vitro by means of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene bleaching tests. The inhibitory potential towards the production of the pro-inflammatory mediator nitric oxide was verified on lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cell line. A remarkable inhibitory activity was observed for the dichloromethane fraction, with an IC50 value equal to 45.86 ± 1.05 μg/mL, a significant result if compared to indomethacin and the known nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), used as positive controls. Moreover, the ethyl acetate fraction proved to be effective in inhibiting pancreatic lipase, an enzyme that plays a pivotal role in the gastrointestinal digestion of dietary fat, suggesting that this species could potentially be a promising source of useful compounds for the treatment of obesity.

Uncovering the Role of p38 Family Members in Adipose Tissue Physiology

The complex functions of adipose tissue have been a focus of research interest over the past twenty years. Adipose tissue is not only the main energy storage depot, but also one of the largest endocrine organs in the body and carries out crucial metabolic functions. Moreover, brown and beige adipose depots are major sites of energy expenditure through the activation of adaptive, non-shivering thermogenesis. In recent years, numerous signaling molecules and pathways have emerged as critical regulators of adipose tissue, in both homeostasis and obesity-related disease. Among the best characterized are members of the p38 kinase family. The activity of these kinases has emerged as a key contributor to the biology of the white and brown adipose tissues, and their modulation could provide new therapeutic approaches against obesity. Here, we give an overview of the roles of the distinct p38 family members in adipose tissue, focusing on their actions in adipogenesis, thermogenic activity, and secretory function.

Browning Effects of a Chronic Pterostilbene Supplementation in Mice Fed a High-Fat Diet

Obesity and related comorbidities are a major health concern. The drugs used to treat these conditions are largely inadequate or dangerous, and a well-researched approach based on nutraceuticals would be highly useful. Pterostilbene (Pt), i.e., 3,5-dimethylresveratrol, has been reported to be effective in animal models of obesity, acting on different metabolic pathways. We investigate here its ability to induce browning of white adipose tissue. Pt (5 µM) was first tested on 3T3-L1 mature adipocytes, and then it was administered (352 µmol/kg/day) to mice fed an obesogenic high-fat diet (HFD) for 30 weeks, starting at weaning. In the cultured adipocytes, the treatment elicited a significant increase of the levels of Uncoupling Protein 1 (UCP1) protein—a key component of thermogenic, energy-dissipating beige/brown adipocytes. In vivo administration antagonized weight increase, more so in males than in females. Analysis of inguinal White Adipose Tissue (WAT) revealed a trend towards browning, with significantly increased transcription of several marker genes (Cidea, Ebf2, Pgc1α, PPARγ, Sirt1, and Tbx1) and an increase in UCP1 protein levels, which, however, did not achieve significance. Given the lack of known side effects of Pt, this study strengthens the candidacy of this natural phenol as an anti-obesity nutraceutical.

Ginsenoside Rb1 Induces Beta 3 Adrenergic Receptor-Dependent Lipolysis and Thermogenesis in 3T3-L1 Adipocytes and db/db Mice

Obesity is constantly rising into a major health threat worldwide. Activation of brown-like transdifferentiation of white adipocytes (browning) has been proposed as a promising molecular target for obesity treatment. In this study, we investigated the effect of ginsenoside Rb1 (Rb1), a saponin derived from Panax ginseng Meyer, on browning. We used 3T3-L1 murine adipocytes and leptin receptor mutated db/db mice. The lipid accumulation, AMP-activated protein kinase alpha (AMPKα)-related pathways, lipolytic and thermogenic factors were measured after Rb treatment in 3T3-L1 adipocytes. Body weight change and lipolysis-thermogenesis factors were investigated in Rb1-treated db/db mice. Beta 3 adrenergic receptor activation (β3AR) changes were measured in Rb1-treated 3T3-L1 cells with or without β3AR inhibitor L748337 co-treatment. As a result, Rb1 treatment decreased lipid droplet size in 3T3-L1 adipocytes. Rb1 also induced phosphorylations of AMPKα pathway and sirtuins. Moreover, lipases and thermogenic factors such as uncoupling protein 1 were increased by Rb1 treatment. Through these results, we could expect that the non-shivering thermogenesis program can be induced by Rb1. In db/db mice, 6-week injection of Rb1 resulted in decreased inguinal white adipose tissue (iWAT) weight associated with shrunken lipid droplets and increased lipolysis and thermogenesis. The thermogenic effect of Rb1 was possibly due to β3AR, as L748337 pre-treatment abolished the effect of Rb1. In conclusion, we suggest Rb1 as a potential lipolytic and thermogenic therapeutic agent which can be used for obesity treatment.

Adipose tissue as a possible therapeutic target for polyphenols: A case for Cyclopia extracts as anti-obesity nutraceuticals

Obesity is a significant contributor to increased morbidity and premature mortality due to increasing the risk of many chronic metabolic diseases such as type 2 diabetes, cardiovascular disease and certain types of cancer. Lifestyle modifications such as energy restriction and increased physical activity are highly effective first-line treatment strategies used in the management of obesity. However, adherence to these behavioral changes is poor, with an increased reliance on synthetic drugs, which unfortunately are plagued by adverse effects. The identification of new and safer anti-obesity agents is thus of significant interest. In recent years, plants and their phenolic constituents have attracted increased attention due to their health-promoting properties. Amongst these, Cyclopia, an endemic South African plant commonly consumed as a herbal tea (honeybush), has been shown to possess modulating properties against oxidative stress, hyperglycemia, and obesity. Likewise, several studies have reported that some of the major phenolic compounds present in Cyclopia spp. exhibit anti-obesity effects, particularly by targeting adipose tissue. These phenolic compounds belong to the xanthone, flavonoid and benzophenone classes. The aim of this review is to assess the potential of Cyclopia extracts as an anti-obesity nutraceutical as underpinned by in vitro and in vivo studies and the underlying cellular mechanisms and biological pathways regulated by their phenolic compounds.

Strategies to target bioactive molecules to subcellular compartments. Focus on natural compounds

Many potential pharmacological targets are present in multiple subcellular compartments and have different pathophysiological roles depending on location. In these cases, selective targeting of a drug to the relevant subcellular domain(s) may help to sharpen its impact by providing topological specificity, thus limiting side effects, and to concentrate the compound where needed, thus increasing its effectiveness. We review here the state of the art in precision subcellular delivery. The major approaches confer "homing" properties to the active principle via permanent or reversible (in pro-drug fashion) modifications, or through the use of special-design nanoparticles or liposomes to ferry a drug(s) cargo to its desired destination. An assortment of peptides, substituents with delocalized positive charges, custom-blended lipid mixtures, pH- or enzyme-sensitive groups provide the main tools of the trade. Mitochondria, lysosomes and the cell membrane may be mentioned as the fronts on which the most significant advances have been made. Most of the examples presented here have to do with targeting natural compounds - in particular polyphenols, known as pleiotropic agents - to one or the other subcellular compartment.

Flavonoids as inducers of white adipose tissue browning and thermogenesis: signalling pathways and molecular triggers

Background

Flavonoids are a class of plant and fungus secondary metabolites and are the most common group of polyphenolic compounds in the human diet. In recent studies, flavonoids have been shown to induce browning of white adipocytes, increase energy consumption, inhibit high-fat diet (HFD)-induced obesity and improve metabolic status. Promoting the activity of brown adipose tissue (BAT) and inducing white adipose tissue (WAT) browning are promising means to increase energy expenditure and improve glucose and lipid metabolism. This review summarizes recent advances in the knowledge of flavonoid compounds and their metabolites.

Methods

We searched the following databases for all research related to flavonoids and WAT browning published through March 2019: PubMed, MEDLINE, EMBASE, and the Web of Science. All included studies are summarized and listed in Table 1.

Result

We summarized the effects of flavonoids on fat metabolism and the specific underlying mechanisms in sub-categories. Flavonoids activated the sympathetic nervous system (SNS), promoted the release of adrenaline and thyroid hormones to increase thermogenesis and induced WAT browning through the AMPK-PGC-1α/Sirt1 and PPAR signalling pathways. Flavonoids may also promote brown preadipocyte differentiation, inhibit apoptosis and produce inflammatory factors in BAT.

Conclusion

Flavonoids induced WAT browning and activated BAT to increase energy consumption and non-shivering thermogenesis, thus inhibiting weight gain and preventing metabolic diseases.

Berberine Promotes Beige Adipogenic Signatures of 3T3-L1 Cells by Regulating Post-transcriptional Events

Induced brown adipocytes (also referred to as beige cells) execute thermogenesis, as do the classical adipocytes by consuming stored lipids, being related to metabolic homeostasis. Treatment of phytochemicals, including berberine (BBR), was reported to induce conversion from white adipocytes to beige cells. In this study, results of microRNA (miRNA)-seq analyses revealed a decrease in miR-92a, of which the transcription is driven by the c13orf25 promoter in BBR-treated 3T3-L1 cells. BBR treatment manipulated the expressions of SP1 and MYC, in turn, reducing the activity of the c13orf25 promoter. A decrease in miR-92a led to an increase in RNA-binding motif protein 4a (RBM4a) expression, which facilitated the beige adipogenesis. Overexpression of miR-92a or depletion of RBM4a reversely interfered with the impact of BBR treatment on the beige adipogenic signatures, gene expressions, and splicing events in 3T3-L1 cells. Our findings demonstrated that BBR treatment enhanced beige adipogenesis of 3T3-L1 cells through transcription-coupled post-transcriptional regulation.

β -Lapachone Regulates Obesity through Modulating Thermogenesis in Brown Adipose Tissue and Adipocytes: Role of AMPK Signaling Pathway

Activation of brown adipose tissue (BAT) has been proposed as a promising target against obesity due to its increased capacity for thermogenesis. In this study, we explored the effect of β -Lapachone ( β L), a compound obtained from the bark of the lapacho tree, against obesity. In vivo administration of β L into either high fat diet (HFD)-induced obese C57BL6 mice and genetically obese Lepr -∕- mice prevented body weight gain, which was associated with tissue weight loss of white adipose tissue (WAT). In addition, β L elevated thermogenic proteins including uncoupling protein 1 (UCP1) and mitochondrial count in BAT and human adipose tissue-derived mesenchymal stem cells (hAMSCs). β L also induced AMP-activated protein kinase (AMPK) phosphorylation, subsequent upregulation of acetyl-CoA carboxylase (ACC) and UCP1, and these effects were diminished by AMPK inhibitor compound C, suggesting that AMPK underlies the effects of β L. Mitogen-activated protein kinase pathways participated in the thermogenesis of β L, specifically p38, c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK1/2) were activated by β L treatment in hAMSCs. Additionally, inhibitors of p38/JNK/ERK1/2 abrogated the activity of β L. Taken together, β L exerts anti-obese effects by inducing thermogenesis mediated by AMPK signaling pathway, suggesting that β L may have a potential therapeutic implication of obesity. Taken together, β L exerts anti-obese effects by not only inducing thermogenesis on brown adipocytes but also inducing the browning of white adipocytes. The anti-obese effect of β L is mediated by AMPK signaling pathway, suggesting that β L may have potential therapeutic implication of obesity.